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3 years ago

The element rhenium (Re) exists as two stable isotopes and 18 unstable isotopes. Rhenium-185 has in its nucleus

Chemistry

1 answer:

sweet [91]3 years ago

8 0

Answer:

d. 75 protons, 110 neutrons

Explanation:

In an isotope, the number next to the number of the atom is the mass number (Protons + neutrons). Rhenium has as atomic number 75, that means Rhenium has <em>75 protons</em>. As atomic mass, 185, is the sum of protons and neutrons, number of neutrons is:

185 - 75 = <em>110 neutrons</em>

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Thus, right answer is:

<em>d. 75 protons, 110 neutrons </em>

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Iron(II) sulfate, an iron supplement , FeSO4 Express your answer to four significant figures and include the appropriate units.

strojnjashka [21]

Answer:

Molar mass = 151.9 g/mol

Explanation:

The molar mass of a compound is obtained by adding u the individual atomic masses in the compound. The unit is g/mol.

In FeSO4, we have one Fe, one S and 4 O.

The atomic masses are given as follows;

Fe = 55.845 u

S = 32.065 u

O = 15.999 u

Molar mass = ( 1 * Fe) + (1 * S) + (4 * O)

Molar mass = (1 * 55.854 ) + ( 1 * 32.065) + (4 * 15.999)

Molar mass = 151.915 g/mol

In four significant figures;

Molar mass = 151.9 g/mol

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3 years ago

Determine how many liters 8.65 g of carbon dioxide gas would occupy at the following conditions.

VashaNatasha [74]

1) 6.17 liters

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3 years ago

How many moles of chromium III nitrate are produced When chromium reacts with 0.85 moles of lead for nitrate to produce chromium

Pepsi [2]

0.85 moles formula units of lead nitrate will produce 0.57 moles formula units of chromium (III) nitrate.

<h3>Explanation</h3>

Typically, the oxidation state of Pb in lead nitrate tend to be +2. In other words, Pb in lead nitrate tends to exist as $\text{Pb}^{2+}$ ions. The formula for a nitrate ion is ${\text{NO}_3}^{-}$ . The charge on each of the nitrate ion is -1. The charge on the two ions should balance. As a result, each $\text{Pb}^{2+}$ ion in lead nitrate would pair up with two ${\text{NO}_3}^{-}$ ions. The formula for lead nitrate will be $\text{Pb}({\text{NO}_3})_2$ . Each formula unit of lead nitrate will contain one $\text{Pb}^{2+}$ ion and two ${\text{NO}_3}^{-}$ ions.

The "III" in the name "chromium (III) nitrate" is a Roman Numeral. It indicates that the oxidation state of Cr in chromium (III) nitrate is +3. The Cr in that compound will exist as $\text{Cr}^{3+}$ . Similarly, each $\text{Cr}^{3+}$ will pair up with three ${\text{NO}_3}^{-}$ ions. The formula for chromium (III) nitrate will be $\text{Cr}(\text{NO}_3})_3$ . Each formula unit of chromium (III) nitrate will contain one ${\text{NO}_3}^{-}$ ion and three ${\text{NO}_3}^{-}$ ions.

0.85 moles formula units of lead nitrate will contain 0.85 × 2 = 1.7 moles of ${\text{NO}_3}^{-}$ ions. Those nitrate ions will end up in 1.7 / 3 = 0.57 moles formula units of chromium (III) nitrate. As a result, the reaction will produce 0.57 moles formula units of chromium (III) nitrate.

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3 years ago

Zoom all the way in to Daphne Major. Describe its appearance in two sentences.

kicyunya [14]

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Ann [662]

Answer:

mol times or devided by molar volume

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